PicoCTF_2017: Raw2Hex

Category: Reverse Engineering Points: 20 Description:

This program just prints a flag in raw form. All we need to do is convert the output to hex and we have it! CLI yourself to /problems/45f3b0abcf176b7cf7c1536b28d05d72 and turn that Raw2Hex!

Hint:

Google is always very helpful in these circumstances. In this case, you should be looking for an easy solution.

Write-up

This seems like another question of bash piping... Running /problems/45f3b0abcf176b7cf7c1536b28d05d72/raw2hex gives us raw binary data, with additional placeholder text infront. That needs to be filtered out first.

# Accomplished by using ':' as a delimiter.
$ /problems/45f3b0abcf176b7cf7c1536b28d05d72/raw2hex | cut -d ':' -f 2

Now, to hex it, we can simply use xxd, the wondertool~

$ /problems/45f3b0abcf176b7cf7c1536b28d05d72/raw2hex | cut -d ':' -f 2 | xxd -plain
cc76ae5c1b19d06897338d2deaa50bf00a

Therefore, the flag is cc76ae5c1b19d06897338d2deaa50bf00a.